Miniature slide handle snap switch



fl' 1957 o. TAYLOR 2,802,077

MINIATURE SLIDE HANDLE SNAP SWITCH Filed Feb. 19, 1954 2 Sheets-Sheet l INVENTOR Owen L.Toylor. MTM ATTORNEY "I on N" H 8 un W- ws N n N w 3 h N v v E w mm: mm my 0 IL M b 8. 3 ww w m WITNESSES: I 477;

Aug. 6,

Filed Feb. 19, 1954 Fig.3.

1957 o. L. TAYLOR MINIATURE SLIDE; HANDLE SNAP SWITCH 2 Sheets-Sheet 2 United States Patent MINIATURE SLIDE HANDLE SNAP SWITCH Owen L. Taylor, Easton, Conn., assignor to The Bryant Electric Company, Bridgeport, Conn., a corporation of Connecticut Application February 19, 1954, Serial No. 411,507 Claims. (Cl. 200-67) My invention relates to electric switches generally, and more particularly to the type of switches which are designated as miniature switches and commonly employed for controlling electrical circuits where space is at a premium.

As the designation miniature switch indicates, such switches are extremely small in size, and accordingly, many additional problems due to such size are encountered. Heretofore, efforts to merely reduce the component parts of prior designs have not proven to be entirely satisfactory, as such reduction have resulted in some cases, in weak structural members and difiicult assembly problems. As can also readily be appreciated, the mere reduction in physical dimensions is not feasible beyond certain design limits. Other miniature switch designs have presented additional difficulties, as due to the small components required, either the durability of the switch is relatively short, or desirable features of the switch were eliminated in order to produce a miniature switch which could be sold at a reasonable and competitive price. Further problems have been encountered in the design of such switches due to small components utilized, such as sticking contacts and slow reaction time.

Accordingly, one object of my invention is to provide a new and improved switch.

Another object of my invetion is to provide a new and improved miniature switch which is readily adapted to be assembled from inexpensive components capable of being mass produced.

Another object of my invention is to provide a new and improved miniature switch having means for positively disengaging sticking contacts.

Another object of my invention is to provide a new and improved miniature switch wherein the action of the moving contacts is independent of the rate of travel of the activating means.

A more specific object of my invention is to provide a new and improved switch which employs a sliding handle for activating pivotally mounted movable contacts.

Still another object of my invention is to provide a new and improved miniature switch which is easily adapted to be utilized as either a single or double-throw switch, which may be either single or double pole.

Another more specific object of my invention is to provide a new and improved switch having a slidable handle for moving a rotatable ball which engages a pivotally mounted moving contact and causes said contact to move.

Another object of my invention is to provide a new and improved snap acting switch which is prevented from stopping at the dead-center position.

Another object of my invention is to provide a new and improved switch wherein the handle provides a kickout feature to prevent sticking of the contacts.

These and other objects of my invention will become more apparent upon consideration of the following detailed description of a preferred embodiment of my 2,802,077 Patented Aug. 6, 1957 invention when taken in conjunction with the following drawings, in which:

Figure 1 is an enlarged, substantially central transverse cross-sectional and partially elevational view of a double pole, double-throw switch constructed in accord ance with the principles of my invention;

Fig. 2 is an enlarged longitudinal sectional view of the switch shown in Fig. 1 taken substantially along the line lL-H thereof and which also illustrates a frag f mentary central section displaced from the line 11-11;

Fig. 3 is an enlarged top plan view of the switch shown in Figs. 1 and 2 with the cover and handle re-' moved, and taken substantially along the line lH-III of Fig. 2;

Fig. 4 is an enlarged top plan view of the switch shown in Fig. 3 with the movable switch member removed; and

Fig. 5 is an enlarged longitudinal sectional view of the switch shown in Fig. 4 taken substantially along the line VV of Fig. 4.

in accordance with this invention, the various stationary and moving contacts for controlling the operation of electrical circuits and operating mechanism therefor are all assembled through a single opening in a formed thin walled housing having a slidable handle mounted on its open side. The sliding handle also carries a spring-biased roller or ball which engages a portion of the moving contact and forces the moving contact to rotate around a fixed point. From the following detailed description, the benefits obtainable from such a design with respect to durability, cost, and simplicity will become apparent. While this invention is hereinafter specifically described with relation to a double pole, a double-throw switch, it is not limited to such a specific arrangement but may be embodied in other types of switches.

The switch assembly shown on the drawings comprises a pre-formed approximately rectangular housing 2 having a base 3, with upwardly extending side walls 4 which are joined together at their ends by upwardly extending end members 6, whereby a central cavity 8 is formed between the side walls 4 and end members 6 above the base 3. As housing 2 contains various electrical circuit controlling means the housing 2 is formed from an insnlating material. As the housing 2 is also formed to receive and locate various electrical components, it is preferably fabricated from an insulating material that may be readily shaped at minimum expense to relatively close tolerances. A material, such as a molded phenolic material, satisfactorily fulfills all these requirements.

At each corner formed by the side walls 4 and the end members 6, a formed upper stationary contact 10, which is fabricated from any suitable electrical conducting material, such as brass or copper strap, is located. Each contact 10 has an approximately inverted J-shape, and comprises a straight back 12 which rests flush against the side wall 4 and extends beyond the housing 2 through an opening in base 3 (not shown), which is similar to the opening 14 in base 3, hereinafter described. Each of the extending portions of contacts 10 is rounded at their ends and are provided with threaded holes 51 by means of which a terminal screw 18 may be secured to the back 12 of each contact 10. Contacts 10 are also provided at their upper ends with integral projections 20, which project inwardly of housing 21 at approximately right angles to the back 12, and which are approximately one half the width of back 12. At the inner end of each projection 20 a downward extending integral contact arm 22 is provided. By this means four contact arms 22 are located at each of the upper corners of housing 2, each of which is inwardly displaced from the adjacent side wall 4 of housing 2.

A formed stationary contact 24, which is fabricated from any suitable electrical conducting material, such as copper or brass, is also provided on each side at the bottom of housing 2, and each comprises a formed longitudinal flat portion 26.which rests flush against the inner side of base 3 of housing 2. Each end of each longitudinal portion 26 is provided with an integral upwardly extending contact arm 28, so that a contact arm 28 is located in each of the lower corners formed by sidewalls 4 and end members 6, spaced directly below the upper contact arms 22. The central portion of each contact 24 at the outer side has an integral extension 16 in the same vertical plan as the back 12 of contacts 10, and it extends through the base 3 of housing 2 through a slot opening 14 (Fig. 1) in base 3. Extensions 16 of contacts 24 are also rounded at their lower ends and are provided with threaded holes 30 whereby a terminal screw 32, which may be identical to terminal screws 18, may be threadedly secured to contacts 24. By this construction a row of terminal screws 18, 32, and 18 in that order, is located at each side of housing 2, which are accessible from the outside of housing 2.

It will also be noted that terminal screws 18 at each end of housing 2, and terminal screws 32 at the center of housing 2 project inwardly towards each other below the housing 2, and in order to prevent accidental cross row shorting of the terminal screws, base 3 is provided with an integral, longitudinal central extension 36 located between the ends of the opposed terminal screws. Extension 36 and base 3 are also provided with integral lateral projections 39 located between adjacent terminals having screws 18 and 32 to prevent accidental shorting of adjacent terminals at each side of housing 2. It is obvious that by connecting a source of power to each terminal screw 32 that each contact 28 would become energized, and by connecting contacts 28 to contacts 10 by means of a moving contact, the terminal screws 18 could be selectively energized.

In view of the small space available within housing 2, it is desirable that contacts 10 and 24 may readily be located and secured in their operating position. Accordingly, a pair of spaced integral projections 5 which extend upward from base 3 have been provided on each sidewall 4 of housing 2, so as to form a centrally located recess 7 therebetween in which the extension 16 of each contact 24 18 received. By this construction each contact 24 may be inserted from the open side of housing 12 and slid into engagement with the inner surface of base 3. As more clearly shown in Fig. 4, the facing sides of contacts 24 are provided with a centrally located recess 9 having projecting tabs 11 which are bendable, by suitable mechanical means, into engagement with notches 13 formed in the lower end of an integral centrally disposed post 40 within the housing 2. To insure that each contact 24 is laterally secure, the base 3 of housing 2 is provided with an integral, longitudinal centrally located projection 34 which is also engaged by a corner of tabs 11 when they are bent to the positions illustrated. Projection 34 also provides additional electrical insulation between contacts 24.

In order to provide for inserting contacts from the open side of housing 2, each end 6 of housing 2 is provided with an integral notch 15, flush with the inner side of the adjacent sidewall 4. In a similar manner each projections 5 is also provided with an integral extension 21 so as to form a notch 23 also flush with the inner side of the adjacent sidewall 4. Notches 15 and 23 are thus arranged in pairs with a pair located at each corner of the housing and with the notches of each pair being longitudinally spaced so that the back 12 of a contact 10 may be freely inserted therebetween. In order to locate contacts 10 on the vertical plane each notch 23 and 15 is provided with an ofiset 19 at its outer end into which laterally extending tabs at each side of the back 12 of contacts 10 extend. It will be noted, however, that projections 5 and their extensions 21 terminate short of the upper edge of housing 2, in order to provide clearance for guides 98 on the handle 86, hereinafter discussed. For the same reason the upper portion of the back 12 of each stationary contact 10 is cut out to provide a shoulder flush with the top of projection 5.

In a switch constructed in accordance with the principles of my invention, flow of current through the switch is controlled by a pair of longitudinally extending moving switch blades 38 which are joined together at an intermediate point by a cross plate 37, which is pivotally supported above the base 3 of housing 2 by the integral upwardly extending tapered post 40. As cross plate 37 carries the switch blades 38, it is fabricated from an insulating material, and for the same considerations with reference to housing 2, is preferably fabricated from fiber or a molded phenolic material. Cross plate 37 is provided at each of its sides with an integral pivot projection 42. The moving contact assembly comprising switch blades 38 and cross plate 37 may be assembled with the housing 2 simply by inserting it through the open side of the housing with cross plate projections 42 received in inwardly extending recesses 46 located at approximately the longitudinal midpoint in each side wall 4 of housing 2 untilthey rest on the bottom lands 44 of these recesses, so that cross plate 37 is thereby pivotally supported with reference to the housing 2. In order to facilitate the pivotal movement of cross plate 37, the projections 42 may be rounded or provided with a taper.

As more clearly shown in Figs. 1 and 2, the post 40 is provided with a reduced area centrally located top extension 50, whereby shoulders 54 are formed at each side of post 40. Cross plate 37 is provided with a centrally located opening 48 in order that cross plate 37 may be placed over the top extension 50 of post 40 with the extension freely received in opening 48 and the plate pivotally supported adjacent each side of top portion 50 by shoulders 54. In order to facilitate the pivotal movement of cross plate 37 on shoulders 54, shoulders 54 are preferably rounded at their upper edges. Thus, it will be noted that cross plate 37 may be pivotally supported on both the side walls 4 of housing 2, and on the shoulders 54 of post 40.

In order to mechanically and electrically engage a pair of fixed contact arms 22 and 28, switch blades 38, which are fabricated from any suitable resilient electrical conducting material, such as a copper or brass alloy, are secured to each side of cross piece 37 by any suitable means. As more clearly shown in Figs. 1 and 3, the central part of each switch blade 38 is approximately U-shaped in section, having a central bight portion 62 and downwardly extending side walls 64. The ends of the bight portions 62 of switch blades 38 are bent upwardly to form extending tabs 58, and as illustrated, switch blades 38 are secured to cross piece 37 by placing tabs 58 in recesses 60 from beneath cross piece 37, with the blades located between the side walls 4 of housing 2 and projection 40, respectively. Tabs 58 are then bent over across the top surface of cross piece 37, and if desired, may be further secured to cross piece 37 by any suitable mechanical means (not shown).

It will be noted that the sides 64 of the central portion of each blade 38 extends longitudinally beyond each end of the bight portion 62 to form opposed contact engaging jaws and they are inclined towards each other from the point where bight portion 62 is bent upward to form tabs 58, so that a narrowed opening 68, which is slightly smaller than the width of stationary contact arms 22 and 28, is provided between sidewalls 64 at each end of the switch blades. By this means, a spring pressure is exerted on stationary contact arms 22 and 28 by the side walls 64 of switch blades 38, as the stationary contact arms 22 and 28 force the blade side walls 64 apart when they engage therebetween. In order to facilitate the spreading of side walls 64 by stationary contact arms 22 and 28 when the switch blades inove into engagement therewith, outwardly turned camr'ning surfaces 52 are provided at the top and bottom edges adjacent the outer end of each blade side wall 64, to first engage the contact arms 22 or 28 during contact closing movement of the switch blades.

In operation, it will be noted that as switch blades 38 are secured to cross piece 37 in the same plane, they will move in unison. Switch blades 38 are also designed so that a pair of stationary contact arms 22 and 28 at alternate corners substantially simultaneously are engaged by each blade, and that upon pivotally moving cross piece 37 over shoulders 54 from one extreme po- Sition to the other, switch blades 38 will disengage one set of alternate contact arms 22 and 28 and engage the other alternate pair of contact arms 22 and 28.

In order to rotate cross piece 37 in the desired manner, a separate subassembly comprising a cover and handle, is provided. As has been indicated, projections of stationary contacts 10 are flush with the upper surface of housing 2 so that when the insulating cover plate 70 is secured over the open top of housing 2, contacts 10 are held securely in their proper position. Cover 70 may be formed from any suitable material, and for the considerations previously mentioned, is preferably fabricated from fiber or a molded phenolic material. A second cover 72, which is fabricated from a stronger material, such as sheet steel, is located above cover 70 and may be formed to a variety of shapes and sizes, depending upon the type of mounting means employed or the method by which it is desired to mount the switch. Covers 70 and 72 are provided with holes 74 and 76, respectively, adjacent each end of the switch which are in alignment with holes 78 in bosses 80 at each of the ends of housing 2 on the center line of housing 2. Covers 70 and 72 may therefore be secured to housing 2 by any suitable means, such as bolts 106, extending through holes 74, 76 and 78. It should be noted that bosses 80 extend between the upper stationary contact arms 22, and that by such construction also provide additional insulation between the upper contacts 22.

Covers 70 and 72 are also provided with aligned. openings 82 and 84, respectively, through which the knob portion 85 of a handle 86 is inserted from beneath so that the undersurface 87 of knob portion 85 slides across the top of the cover 72. As will become apparent from the description that follows, handle 86 must be inserted through openings 82 and 84 prior to securmg the covers 70 and 72 to the housing 2. to provide means for activating the cross piece 37, the handle 86 is provided with a downwardly extending central post 88 having a tapered cylindrical bore 90 therein which terminates in a fiat bottom land 92 upon which an operating spring 94 is positioned within bore 90.. i

As illustrated, a closed end of the helical spring 94,. which may be fabricated from any suitable spring material such as phosphor-bronze alloy, is provided to engage a round ball 96 which is partially received by the lower closed end coil of the helical spring 92. Wherr the switch is assembled, the ball 96 is engaged by the spring 94 with the latter compressed so as to cause the ball 96 to engage the cross piece 37 under pressure at a point between the tabs 58, and in a longitudinal linewith the top portion of post 40. It will be noted that the top portion 50 of post 40 projects slightly beyond the top of cross piece 37. Further, it will be noted that in order to prevent handle 86 from being removable from the top of the switch, guides 98 are provided. integral with handle post 88 at each side which project: outwardly from the post 88 and engage the underside of cover 70. By this construction all the movable parts of the switch are held in operating position by cover 70..

Referring to the position of the switch as shown in Figs. 1 and 2, it will be noted that when a pair of supply In order a conductors are connected to each of the terminal screws 32, the bottom stationary contacts 24 and their integral contact arms 28 become energized. As shown, switch blades 38 on each side of cross piece 37 slope downward to the right so that the side walls 64 of the switch blades 38 are in engagement with the contacts 28 at the right (Fig. 2) and are also in engagement with the upper lefthand stationary contact arms 22 of contacts 10. As con-' tacts 10 are thus energized through switch blades 38, the left terminal screws 18 are energized. It is obvious that any particular circuit that it may be desired to control may be connected to the left terminal screws 18. In this position of the switch blades 38, the handle 86 is at its extreme right-hand position, and the ball 96 is in engagement with cross piece 37 at the extreme right-hand position.

As more clearly shown in Figs. 2 and 4, bosses and projection 34 are joined together by offsets 81 which project inwardly from bosses 80 into cavity 8 along the horizontal centerline of housing 2. Offsets 81 extend upwardly from projection 34 and are terminated at or slightly above the center of ball 96 in order to provide a stop with reference to the longitudinal travel of ball 96. Thus, with cross plate 37 sloping downwardly to the right, as shown in Fig. 2, ball 96 will be held by a component of the force of spring 94 urging ball 96 into engagement with both cross plate 37, and the right-hand offset 81. This same component of the force exerted by spring 94 also causes the spring to move toward the right side of the handle bore 91 and maintain the handle at an extreme right-hand position. Movement of handle 86 to the left will force the spring 94 and the retained ball 96 leftward up the sloping surface of the cross piece 37, causing the helical spring 94 to be compressed between sloping cross plate 37 and bottom land 92 of bore of handle 86. It will be noted that as top portion 50 of the stationary post 40 extends above the top surface of cross plate 37, movement of ball 96 over top portion 50 will also cause spring 94 to be further compressed. In the event handle 83 is not moved a sufficient distance leftward to cause the ball 96 to move over top portion 50, the force of spring 94 will cause the handle 86 and ball 96 to return to their initial at rest position.

One of the features of my invention resides in the fact that the spring 94 and ball 96 cooperate to hold the cross piece 37 stationary until the ball 96 rides over the rounded top portion 50. When handle 86 has moved sufiiciently to cause the ball 96 to pass over the top portion 50 so that the ball 96 is then on the other side of the fulcrum points of cross piece 37 whereat the energy utilized in compressing spring 94 is suddenly released at this point and becomes suddenly available to cause counterclockwise rotation of switch blades 38 and cross piece 37. It is to be particularly noted that during switch operating movement of the handle, the center line of spring 94 is initially inclined downwardly to the right of the vertical center line, and when ball 96 clears top portion 50 and the cross piece 37 starts to rotate, at that instant the ball 96 and spring 94 will be in an unstable state relative to the handle. Spring 94 can rapidly release its stored energy by forcing ball 96 down cross piece 37 to the left independently of handle movement until spring 94 again reaches a stable state against the left offset 81. Thus, it will be noted that by this assembly the switch blades will be held in engagement with one set of stationary contacts until receiving a suddenly applied counter rotating force causing switch blades 38 to rapidly move into engagement with the upper right contact arm 22 and the lower left contact arm 28.

In the event the spring pressure is insuflicient to cause such rotation, as may infrequently occur due to the welding of the contact arms 22 or 28 to the side walls 64 of switch blades 38, the sloped edge 102 on the forward side of the post 88 of handle 86 will engage the upwardly tilted end of cross piece 37 and positively force (i. e. kick out) side walls 64 of switch blades 38 out of engagement with contact arms 22 and 28. Once such separation occurs the compressed energy in spring 94 will cause the cross piece 37 to rapidly rotate around its fulcrum point. It will also be noted that offsets 81 terminate below edges 102 1n order to provide clearance for operating handle 86.

Inasmuch as the entire assembly is symmetrical around its horizontal and vertical center it is obvious that the switch can be operated to pivot around post 40 and energize either the left or the right set of terminals 18 as desired. Also, as the rounded top portion 50 projects above cross piece 37, ball 96 is unable to stop in the dead center position. Another feature of my invention resides in the fact that the action of the moving contacts is independent of the rate of travel of the handle 86. It will be noted that although the movement of handle 86 causes the compression of spring 94 the rate of movement does not effect the total quantity of energy stored, but only afiects the rate of such energy storage. Thus, regardless of the rate of handle movement, a predetermined energy quotient is always available for causing rotation of the moving contact. Also, once handle 86 has moved sufficiently to force ball 96 over top portion 50 the switch blades 33 will rotate at the same rate regardless of whether handle 86 is moved beyond such position. Thus, by this design a true snap action of the moving contacts is obtained.

As has been indicated, the switch shown is of the double pole, double-throw type which utilizes two switch blades 38. However, if desired, a single pole, double-throw switch or a single throw, single pole switch could be provided within the scope of this invention merely by eliminating either pair of outside contacts 10 and by eliminating the corresponding switch blade 38. If one of the outside stationary contacts 10 is eliminated, it will be noted that the terminal screws 18 associated therewith will also automatically be eliminated. In the event that the entire assembly is held together by means of securing elements having a head, for example, such as the head of bolt 1%, the under side of handle knob 85 may be provided with a centrally positioned longitudinal slot 104 to clear it.

It should be noted that the switches of this type may be made having extremely small dimensions, and in some cases having an overall height of approximately an inch, an overall width of approximately of an inch and an overall length of approximately 1% inches. As a switch constructed in accordance with my invention has relatively simple components, such components can easily be reduced or enlarged in size as desired, and retain all of the desirable features and strength. Throughout the description of my invention, the terms downward and leftward, upper and lower, etc. have been utilized in order to more clearly describe the construction of my switch in connection with the positions occupied by the parts on the drawings. It is to be realized, however, that such nomenclature is for convenience in discussion only and should not be construed or considered as limiting.

Accordingly, having described a preferred embodiment of the invention in accordance with the patent statutes, it is desired that the invention be not limited to the specific construction illustrated, inasmuch as it will be apparent that many modifications in addition to those specifically pointed out herein may be made without departing from the broad scope and spirit of this invention. Accordingly, it is desired that this invention be interpreted as broadly as possible and that it be limited only as required by the prior art.

I claim as my invention:

1. An electrical switch comprising a housing having a fixed contact mounted therein, an elongated contact, a support for pivotally supporting said elongated contact in said housing along a lateral axis of said elongated contact so as to be movable into and out of engagement with said fixed contact, an opening in said elongated 4 8 contact extending on both sides of said pivot axis, said support having a portion extending through and slightly beyond said opening, and reciprocating operating means engageable with said elongated contact and longitudinally slidable therealong past said pivot axis so as to engage said portion of said support for causing said elongated contact to oscillate between fixed limits through an are around said support whereby said separable contacts may be held in or out of engagement.

2. An electrical switch comprising a housing having a fixed contact mounted therein, an elongated contact located within said housing having a laterally extending opening therein terminating short of the sides so as to form a pair of laterally spaced substantially parallel side portions, a support located within said housing having a pair of spaced shoulders engageable with said side portions on one side of said contact whereby said contact may be pivoted thereabout, said support having a portion between said shoulders extending through said opening and therebeyond to the other side of said contact, and reciprocating operating means engageable with the other side of said contact and longitudinally slidable therealong so as to pass over said portion of said support whereby said contact is caused to oscillate between fixed limits through an are around said support and said contacts may be held in or out of engagement.

3. A housing for an electrical switch comprising a formed body having a base from which extend joined side and end walls, a projection extending upwardly from said base approximately midway between said side and end walls, said projection having a shoulder at two of its opposed sides with the portion therebetween extending upwardly beyond said shoulders so that an elongated plate with an opening therein may be pivotally supported at each side of the opening by said shoulders engaging one side of said plate and so that said portion of said projection may extend beyond the other side of said plate through said opening, and means integral with said side and end walls for receiving various switch components.

4. An electrical switch comprising a hollow elongated casing having an inwardly facing fulcrum, separable contact means disposed within said casing one of which is movable into and out of engagement with the other, said movable contact means being elongated and pivotally supported on one side along a lateral axis by said fulcrum, operating means slidably supported by said casing including a spring biased roller in engagement with the other side of said movable contact means, said operating means being movable rectilinearly to cause said roller to move to either side of said fulcrum whereby said movable contact means oscillates between fixed limits around said fulcrum and said separable contacts may be held in or out of engagement, and said operating means having a projecting portion for directly engaging said movable contact means to force said separable contacts apart when said spring biased roller does not have sufficient force to cause oscillation of said movable contact means.

5. An electrical switch comprising an insulating housing having a fixed contact mounted thereon, an elongated movable contact, a support within said housing engageable with one side of said movable contact along a lateral axis thereof for pivotally supporting said movable contact means, rectilinearly slidable operating means mounted on said-housing, spring biased operating means movably engaging the other side of said movable contact means, said slidable means having means engageable with said spring biased operating means for causing said spring biased operating means to move linearly with the slidable means over said movable contact means to either side of said axis whereby said movable contact means is pivotally oscillated, and said engaging means on said slidable means being of a size to permit lost motion thereof relative to at least a part of said spring biased operating means so as to obtain limited displacement of said spring biased operating means with relation to said slidable means when said slidable means is moved over said axis of said movable contact means.

6. An electric switch comprising separable contact means one of which is movable into and out of engagement with the other, said movable contact means including a member having a substantially flat surface with an aperture therein, a housing including a support for pivotally supporting said movable contact means therein and having a portion extending through said aperture so as to extend above said flat surface, a handle mounted on said housing, a spring biased operating member engaging said handle and said flat surface of said member, said handle being linearly movable on said housing and having means for causing said operating member to move linearly along said flat surface across the pivot axis of said movable contact to either side thereof, and said portion of said support being located on said pivot axis and in the path of movement of said operating member whereby until said operating member has traveled over said portion said movable contact means cannot be actuated.

7. A support for an electrical switch comprising an insulating base having a projection extending outwardly therefrom, said projection being formed to provide a pair of spaced aligned shoulders which have a configuration so as to form a pivot axis above said base, and the portion of said projection between said shoulders passing through said pivot axis and extending outwardly therebeyond.

8. An electrical switch including a base of insulating material having a fixed contact mounted thereon, a projection extending outwardly from said base which is formed to provide a pair of spaced aligned shoulders equidistant above said base having a configuration to form a pivot axis, a plate with an elongated opening therein mounted on said projection so that said shoulders engage one side thereof at opposite ends of said opening, the central portion of said projection between said shoulders being of a size to be received within said opening and of a length to extend slightly beyond the other side of said plate, a movable contact secured to said plate, and movable means secured to said support including means engageable with said other side of said plate and movable across said central portion of said projection to cause said plate to pivot about said pivot axis and move said movable contact into and out of engagement with said fixed contact.

9. An electrical switch comprising a cup-shaped housing of insulating material, means in opposed walls of said housing for pivotally supporting a plate therebetween 5 above the base thereof, movable means mounted in said housing including means engageable with the upper surface of said plate and movable rectilinearly thereacross through the pivot axis of said plate and to each side thereof, a fixed contact secured to said housing, a movable contact secured to said plate and movable into and out of engagement with said fixed contact upon pivotal movement of said plate, an opening in said plate extending along the pivot axis thereof, a projection extending upwardly from said base having an upper end extending slightly beyond the upper surface of said plate and in the path of movement of said engageable means for preventing said engageable means from being located at said pivot axis.

10. An electrical switch comprising an inuslating housing having spaced means extending upwardly from a base for pivotally supporting an elongated plate therebetween above said base, a handle mounted on said housing above said plate so as to be rectilinearly slidable with respect to said housing to and from either side of the pivot axis of said plate, a spring biased operating member engaging said handle and the upper surface of said plate, projecting means on said handle engageable with said operating member to cause said operating member to move rectilinearly over the upper surface of said plate and to either side of said pivot axis, a fixed contact secured to said housing, a movable contact secured to said plate so as to be movable into and out of engagement with said fixed contact upon pivotal movement of said plate, and said projecting means being engageable with the upper surface of said plate upon such rectilinear movement for initiating pivotal movement of said plate if said operating member is unable to do so.

References Cited in the file of this patent UNITED STATES PATENTS 1,605,910 Appleton et al. Nov. 9, 1926 1,812,914 Williams et al. July 7, 1931 1,889,637 Cook Nov. 29, 1932 1,912,607 Watts June 6, 1933 2,027,538 Krieger Jan. 14, 1936 2,050,698 Gaynor Aug. 11, 1936 2,095,176 Douglas Oct. 5, 1937 2,171,368 Krieger Aug. 29, 1939 2,267,203 Krieger Dec. 23, 1941 2,377,134 Dietrich May 29, 1945 2,469,274 Rein May 3, 1949 FOREIGN PATENTS 174,137 Great Britain Jan. 9, 1922 319,194 Germany Feb. 26, 1920 534,961 Great Britain Mar. 24, 1941 

